[atrueb]

I really love the sportive looks of the 310m and I'd love to put them on my x3. I am however concerned about the weight. My 2l diesel runs perfectly well with the 19" 369m rims: good acceleration and smooth cruising at 1000rpm. Last summer I bought 20" kelleners and unfortunately the acceleration decreased and cruising at 1000rpm is not at all smooth (vibration.... It runs better if I shift down a gear, but the automatic shifts up again). Obviously the kelleners seem to be heavy which results in the sluggish performance out of my 2l diesel.

So I am wondering if the 310m may be better / lighter? My neighborhood bmw dealer told me that I would not feel a difference between 369m and 310m, and assured me that bmw would not offer the 310m for the 4 bangers if they would negatively influence the ride... he also added that non-oem wheels often don't work as well as oem, which are specifically designed for that car.

Not sure whether he is being honest or just wants to sell me a set of 310m! I am sure that on a 6 cylinder, the weight will be neglectable.... But what about on a 4 banger? The last thing I want to do is buy 310m to only realize that the performance is no good.

Any thoughts on this out there?

[mge92]

I have the 310M on my 28i N20 and from what I can tell all that is negatively impacted is the fuel economy. Acceleration might be slightly impacted but the difference is barely noticeable. I cannot comment on how your roads are in Switzerland but the 310M rides well if the roads are smooth but if there are huge pot-holes, which we have all over the USA, they really don't like them and may cause the car to shudder a little.

[atrueb]

Thanks. As the 28i has max torque at 1250rpm, and the 20d/28d has it at 1750rpm, that could explain why you hardly feel a difference. Once I get more torque at 1500rpm my diesel is also "happy". It's mostly the cruising in low revs (like 1000rpm ) which annoys me. Sports mode (1700rpm) is great, but comfort and eco are no good.
Excited to hear what other people think;-)